Biodegradation of polylactic acid (PLA) fibers using different enzymes

The biodegradability of polylactic acid (PLA) nonwovens was evaluated using enzymatic degradation. To evaluate enzyme biodegradation, three enzymes, lipase, esterase, and alcalase, which are known to hydrolyze PLA effectively, were selected. Degradation time was determined under optimal enzyme treatment conditions. Enzymatic degradation affected the width and thickness of PLA nonwovens. In addition, the degree of crystallinity of the PLA nonwovens increased with time for the first 21 days of enzyme biodegradation and then decreased. Alcalase was more efficient than lipase and esterase in degrading the PLA nonwovens. Degradation was found to create cracks on the fiber surface, making the fibers rough. Weight loss and change in tensile strength were not significant, and the observed changes could be due to the cracks on the surface. Our findings propose the mechanism of enzymatic degradation of PLA nonwovens, which might be useful for waste management in the textile industry.